If the conference calls that come with earnings reports attracted exhausted travelers instead of financial analysts and journalists, there's no way Delta, United, American, and Southwest could make it through the week without getting an earful about the agonies of boarding an airplane.

While airlines policies vary—there is no standard accepted way of loading passengers—any "eye test" indicates that having travelers line up at the gate, only to wait again inside the plane, isn't efficient. Data back this up: Boeing's research showed that boarding a plane was 50 percent slower in 1998 than in 1970. "Boeing believes that these trends will continue," the study noted, "unless the root causes are understood and new tools and processes are developed to reverse the trend."

From a data-driven perspective, this is nothing short of maddening. There are many ways to board a plane, with "back-to-front"—the chosen boarding process of most U.S. carriers—the slowest. It is so ineffective that timed research shows that simple random boarding ends up being faster.

One possibility is that airlines have no incentive to improve the process. As long as it remains terrible, they can sell early boarding privileges. Southwest, for example, charges $40 to be among the first 15 to board. Consider the indignity: The stress of boarding is so bad that people are willing to pay money to wait in the plane, rather than outside it—and they pay money to the very company causing that stress.

Getting on a plane is so complicated that Southwest even has a 12-question FAQ devoted to boarding. It's simply not possible that a boarding procedure that looks like the one below is set up with customers' best interests in mind.

Another minor perk that's growing throughout the industry is the increased use of zone boarding as a way for airlines to reward passengers with a small status perk. Just owning a Delta Amex Card brings early boarding privileges. These customers may not be able to upgrade to a higher class, but they can be consoled by making it to their bad seat earlier than others.

By charging money for checking bags, airlines encourage passengers to bring as much luggage as possible on board. That can only slow down the boarding process while simultaneously making it more stressful: What if there's no more room for your carry-on? More reason to push to the front of the line or shell out for early boarding privileges. (United Airlines recently said it would crack down on oversized carry-on luggage—a move that could speed up boarding and generate more revenue at the same time.)

To be fair, some airlines are trying: American Airlines spent two years studying its boarding process and landed on a randomized, zone-based system. Last year it introduced a tweak that gives a slightly higher priority to passengers who have no carry-ons for the overhead bin. United uses an "outside-in" boarding process by which people with window seats board ahead of those on the aisle. This is a version of what's known as the Steffen Method, after astrophysicist Jason Steffen's 2008 research paper (PDF) offering a mathematically sounder approach to efficient boarding. A reality show producer recruited Steffen for a video segment about it; yet, three years after his paper was published, none of the major airlines had asked him for help.